Identification of the lateral organ boundary domain gene family and its preservation by exogenous salicylic acid in Cerasus humilis

Abstract

The gene family known as the Lateral Organ Boundary Domain (LBD) is responsible for producing transcription factors unique to plants, which play a crucial role in controlling diverse biological activities, including their growth and development. This research focused on examining Cerasus humilis'ChLBD gene, owing to its significant ecological, economic, and nutritional benefits. Examining the ChLBD gene family's member count, physicochemical characteristics, phylogenetic evolution, gene configuration, and motif revealed 41 ChLBD gene family members spread across 8 chromosomes, with ChLBD gene's full-length coding sequences (CDSs) ranging from 327 to 1737 base pairs, and the protein sequence's length spanning 109 (ChLBD30)-579 (ChLBD35) amino acids. The molecular weights vary from 12.068 (ChLBD30) to 62.748 (ChLBD35) kDa, and the isoelectric points span from 4.74 (ChLBD20) to 9.19 (ChLBD3). Categorizing them into two evolutionary subfamilies: class I with 5 branches, class II with 2, the majority of genes with a single intron, and most members of the same subclade sharing comparable motif structures. The results of collinearity analysis showed that there were 3 pairs of tandem repeat genes and 12 pairs of fragment repeat genes in the Cerasus humilis genome, and in the interspecific collinearity analysis, the number of collinear gene pairs with apples belonging to the same family of Rosaceae was the highest. Examination of cis-acting elements revealed that methyl jasmonate response elements stood out as the most abundant, extensively dispersed in the promoter areas of class 1 and class 2 ChLBD. Genetic transcript analysis revealed that during Cerasus humilis' growth and maturation, ChLBD developed varied control mechanisms, with ChLBD27 and ChLBD40 potentially playing a role in managing color alterations in fruit ripening. In addition, the quality of calcium fruit will be affected by the environment during transportation and storage, and it is particularly important to use appropriate means to preserve the fruit. The research used salicylic acid-treated Cerasus humilis as the research object and employed qRT-PCR to examine the expression of six ChLBD genes throughout storage. Variations in the expression of the ChLBD gene were observed when exposed to salicylic acid, indicating that salicylic acid could influence ChLBD gene expression during the storage of fruits. This study's findings lay the groundwork for additional research into the biological role of the LBD gene in Cerasus humilis.